1. Field of the Invention
The present invention relates to an apparatus and method for manufacturing a solidified salt that is easy to treat in size and shape by using a vacuum transfer and a dual vessel, and more particularly, to an apparatus and method for quantitative solidification of a molten salt by using a vacuum transfer and a dual vessel, in which a molten salt is stably discharged to a mold by quantitatively transferring the molten salt at a vacuum pressure within the dual vessel, and a predetermined size and shape of a solidified salt is manufactured, thereby processing and collecting the solidified salt safely.
2. Description of the Related Art
A molten salt has been widely applied in a variety of industrial technologies because of its inherent physical and chemical properties, that is, high electrical conduction, material transfer, and fluid properties. In recent years, the molten salt is actively used in many technical fields, including metal manufacture and purification, fuel cell, and so on.
In a process using a molten salt as a reaction medium, a sequential operation is impossible because a salt is solidified at a temperature below a melting point. Accordingly, a batch reactor is used for stepwise operations.
Due to deliquescence of salt, the process of molten salt requires operating conditions of inert atmosphere. Accordingly, it is difficult to transfer the molten salt out of the reactor for the purpose of purifying or recycling the salt or reusing the salt in a subsequent process.
Specifically, a large amount of the molten salt is used as a reaction medium in a metal manufacture and purification. After finishing the process, a large volume of the molten salt needs to be discharged out of the vessel and divided and solidified into a proper size and shape of a salt in order to easily process the molten salt in a subsequent process.
However, salt mass solidified in a discharge passage must be dissolved in order to re-discharge the molten salt out of the vessel after its discharge is paused.
As one example, the solidified salt can be dissolved using an O2 lance. However, this method is very dangerous and cannot be applied when an access to an apparatus is not easy. In order to solve this problem, PCT Application No. PCT/EP97/05469 discloses a method of melting the solidified melt by supplying an electromagnetic energy at a side of a discharge passage.
If such a conventional method is applied to a quantitative discharge of a molten salt, a salt mass is easily molten, but a molten salt cannot be quantitatively discharged. In addition, the molten salt cannot be rapidly discharged due to a melting time of the salt mass. Meanwhile, a mold is inevitably used to solidify the molten salt in a predetermined size and shape.
When the solidified material is attached to the mold, it is difficult to separate the solidified material from the mold. A method for solving this problem is disclosed in PCT Application No. PCT/EP97/06197; in which a mold containing a molten salt can be quickly cooled by immersing the mold in a low-temperature liquid. However, the mold must be vertically dropped down from an outside of a heater in order for the cooling. Also, it is difficult to prevent heat loss of the heater.
The conventional apparatus and method for discharging the molten salt cannot quantitatively solidify the molten salt in a size and shape easy to treat. Accordingly, there is a demand for an apparatus and method that can quantitatively discharge the molten salt and rapidly solidify it in a proper size and shape.